That cheezy Tom Hanks movie, Mazes and Monsters, is actually based on a true story of some crazy guy who enacted a real-life D&D campaign and lived in some steam tunnels and eventually killed himself. Of course, the person had mental problems.

Apart from that, I don't think there's any legitimate criminal cases where anyone killed anyone because of D&D, apart from maybe a few cases involving minors where they basically said it was D&D because their lawyers told them to.

and Monsters is based in large part on the largely apocryphal "steam tunnel incidents" of the late 1970s. These urban myths developed during the infancy of role playing games, generally purporting that university students playing a live action version of Dungeons & Dragons or similar game disappeared into the utility tunnels of the school and became lost, and in some cases died of hypothermia or other causes.

However, there was one case of a person going into underground tunnels.

Egbert was a 16 year old child prodigy who was battling intense academic pressure, drug addiction, and personal issues. He had entered Michigan State University's utility tunnels with the intent of committing suicide and went into hiding after that attempt. After learning that Egbert had played Dungeons and Dragons, Dear, who was unfamiliar with the game, suggested that Egbert may have entered the tunnels to play a live action version of the game. This theory was taken as fact by the media and caused intense controversy over the psychological effects of role playing games. After several weeks, Egbert gave himself up to Dear.

https://en.wikipedia.org/wiki/Mazes_and_Monsters_%28novel%29 https://en.wikipedia.org/wiki/The_Dungeon_Master

I definitely heard those myths in the wild in grade school, as late as 1988.

In the mid 90s a local convenience store posted a warning about LSD-laced Mickey Mouse tattoos, too.